Ever so often there is a complaint that a vehicle is suddenly using too much oil. Apparently, it isn’t leaking out of the case or getting past the piston rings. A little detective work will sometimes show that the missing oil is passing through a cracked diaphragm on the windshield wiper booster pump, and going into the intake manifold. That’s one way of oiling the valve stems but at the same time it isn’t doing the carburetor adjustment a bit of good. Any kind of an air leak in the intake system places the carburetor behind the eight ball and should be attended to before giving the carburetor a bad name.
But let us suppose that the linkage is all tight in the joints, all flanges have good snug gaskets, the automatic choke is functioning correctly, the vacuum diaphragms in the distributor automatic advance and windshield booster pump are not leaking, and that everything we’ve mentioned so far is just as it should be. Yet there can be be something that will give the carburetor all the symptoms of a sick headache. You’ve guessed! The exhaust system!